PP-ELASTOMER-FILLER HYBRIDS .1. PROCESSING, MICROSTRUCTURE, AND MECHANICAL-PROPERTIES

Three-component systems with a polypropylene (PP) matrix consisting of polar elastomer (ethylene-propylene rubber and styrene-ethylene-butyl ene-styrene grafted with maleic anhydride) or of polar PP (PP grafted with maleic anhydride) and filler were investigated. Three microstruct ures of PP-elastomer-filler hybrids were obtained by processing contro l and elastomer or PP modification with the maleic anhydride: fillers and rubber particles were separated in the PP matrix, rubber particles with filler core were distributed in the PP matrix, and mixed microst ructures of the first and second. A study of mechanical properties sho wed that the elastic modulus increased in the first microstructure and impact strength increased in the second microstructure. Mechanisms fo r the relationships between microstructure, processing, and mechanical properties are discussed. (C) 1996 John Wiley & Sons, Inc.